/* 
    NekoBIN - style.css
    Design System: Premium, Warm, Cinematic, Elegant
*/

:root {
    /* Colors */
    --color-bg: #F9F8F6; /* オフホワイト / 生成り */
    --color-text-main: #333333;
    --color-text-sub: #5D4037; /* 木目に合うブラウン */
    --color-accent: #B8860B; /* アンティークゴールド */
    --color-accent-soft: #D4AF37;
    --color-deep: #1A237E; /* 深いネイビー */
    --color-natural: #556B2F; /* オリーブグリーン */
    --color-white: #FFFFFF;

    /* Fonts */
    --font-serif: 'Shippori Mincho', serif;
    --font-sans: 'Noto Sans JP', sans-serif;

    /* Spacing */
    --space-unit: 1rem;
    --container-width: 1200px;
    --transition-premium: 1.2s cubic-bezier(0.165, 0.84, 0.44, 1);
}

/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html, body {
    overflow-x: hidden;
    width: 100%;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    background-color: var(--color-bg);
    color: var(--color-text-main);
    font-family: var(--font-sans);
    line-height: 1.8;
    -webkit-font-smoothing: antialiased;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* Background Texture (Refined Linen/Paper feel) */
.noise-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    opacity: 0.04;
    z-index: 9999;
    /* Noise + Subtle Fabric Pattern */
    background-image: 
        url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.65' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)'/%3E%3C/svg%3E"),
        linear-gradient(45deg, rgba(0,0,0,0.02) 25%, transparent 25%, transparent 75%, rgba(0,0,0,0.02) 75%, rgba(0,0,0,0.02)),
        linear-gradient(45deg, rgba(0,0,0,0.02) 25%, transparent 25%, transparent 75%, rgba(0,0,0,0.02) 75%, rgba(0,0,0,0.02));
    background-size: 200px 200px, 4px 4px, 4px 4px;
    background-position: 0 0, 0 0, 2px 2px;
}

/* Typography */
h1, h2, h3, .logo {
    font-family: var(--font-serif);
    font-weight: 500;
}

a {
    text-decoration: none;
    color: inherit;
    transition: 0.3s ease;
}

/* Layout */
.container {
    width: 90%;
    max-width: var(--container-width);
    margin: 0 auto;
}

/* Header */
header {
    position: fixed;
    top: 0;
    width: 100%;
    padding: 1.5rem 0;
    background: rgba(249, 248, 246, 0.8);
    backdrop-filter: blur(10px);
    z-index: 1000;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 90%;
    margin: 0 auto;
}

.logo {
    font-size: 1.5rem;
    letter-spacing: 0.1em;
    color: var(--color-text-sub);
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-links a {
    font-size: 0.9rem;
    letter-spacing: 0.05em;
    color: var(--color-text-main);
}

.nav-links a:hover {
    color: var(--color-accent);
}

/* Hero Section */
.hero-section {
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background: linear-gradient(rgba(0, 0, 0, 0.1), rgba(0, 0, 0, 0.1)), url('cute_monotone_cat_hero_1777551936436.png');
    background-size: cover;
    background-position: center;
    background-attachment: fixed; /* Simple Parallax */
    position: relative;
    overflow: hidden;
}

@media (max-width: 1024px) {
    .hero-section {
        background-attachment: scroll; /* Mobile fix for backgrounds */
    }
}

.hero-section::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 30vh;
    background: linear-gradient(to top, var(--color-bg), transparent);
}

.hero-content {
    position: relative;
    z-index: 10;
}

.hero-content h1 {
    font-size: clamp(2rem, 8vw, 3.375rem);
    line-height: 1.2;
    margin-bottom: 1.5rem;
    color: var(--color-white); /* 白に変更 */
    text-shadow: 0 2px 20px rgba(0, 0, 0, 0.2);
}

.sub-copy {
    font-family: var(--font-serif);
    font-size: clamp(1rem, 4vw, 1.6rem);
    font-weight: 500;
    letter-spacing: 0.25em;
    color: var(--color-accent-soft); /* 黄色（アンティークゴールド）に変更 */
    margin-bottom: 3rem;
    opacity: 1;
}

/* Buttons */
.cta-group {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
}

.btn {
    padding: 1rem 2.5rem;
    font-size: 0.9rem;
    letter-spacing: 0.1em;
    border-radius: 0; /* Sharp, elegant edges */
    transition: 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
    cursor: pointer;
}

.btn-primary {
    background-color: var(--color-text-sub);
    color: var(--color-white);
    border: 1px solid var(--color-text-sub);
    position: relative;
    overflow: hidden;
}

/* Brass Shine Effect on Hover */
.btn-primary::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: linear-gradient(
        45deg,
        transparent,
        rgba(255, 255, 255, 0.1),
        rgba(255, 255, 255, 0.2),
        rgba(255, 255, 255, 0.1),
        transparent
    );
    transform: rotate(45deg);
    transition: 0.6s;
    opacity: 0;
}

.btn-primary:hover::after {
    left: 100%;
    opacity: 1;
}

.btn-secondary {
    background-color: transparent;
    color: var(--color-text-main);
    border: 1px solid var(--color-text-main);
}

.btn-secondary:hover {
    background-color: var(--color-text-main);
    color: var(--color-white);
}

/* Animations */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp 1.8s forwards cubic-bezier(0.165, 0.84, 0.44, 1);
    letter-spacing: 0.05em; /* Start slightly tighter */
}

.hero-content h1.fade-in { 
    animation-delay: 0.3s;
    animation-name: fadeInUpBreathing;
}
.sub-copy.fade-in { animation-delay: 0.7s; }
.cta-group.fade-in { animation-delay: 1.1s; }

@keyframes fadeInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Breathing animation for key copy */
@keyframes fadeInUpBreathing {
    0% {
        opacity: 0;
        transform: translateY(20px);
        letter-spacing: 0.05em;
    }
    100% {
        opacity: 1;
        transform: translateY(0);
        letter-spacing: 0.15em; /* Expand slowly like a breath */
    }
}

/* Section Common */
section {
    padding: 8rem 0;
}

.section-title {
    font-size: 3rem;
    text-align: center;
    margin-bottom: 5rem;
    color: var(--color-text-sub);
    letter-spacing: 0.2em;
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -1.5rem;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 1px;
    background: var(--color-accent);
}

.title-paw {
    display: inline-block;
    vertical-align: middle;
    margin-left: 1rem;
    width: 30px;
    height: 30px;
    opacity: 0.8;
}

/* Mobile Menu Button */
.menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 30px;
    height: 21px;
    cursor: pointer;
    z-index: 1001;
}

.menu-toggle span {
    display: block;
    width: 100%;
    height: 2px;
    background-color: var(--color-text-sub);
    transition: 0.3s ease;
}

@media (max-width: 768px) {
    .menu-toggle {
        display: flex;
    }

    .nav-links {
        display: none;
        position: fixed;
        top: 0;
        right: 0;
        width: 80%;
        height: 100vh;
        background: var(--color-bg);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        box-shadow: -10px 0 30px rgba(0,0,0,0.1);
        z-index: 1000;
    }

    .nav-links.active {
        display: flex;
    }

    .nav-links li {
        margin: 1.5rem 0;
    }

    .nav-links a {
        font-size: 1.2rem;
    }

    /* Hamburger Animation */
    .menu-toggle.active span:nth-child(1) {
        transform: translateY(9.5px) rotate(45deg);
    }
    .menu-toggle.active span:nth-child(2) {
        opacity: 0;
    }
    .menu-toggle.active span:nth-child(3) {
        transform: translateY(-9.5px) rotate(-45deg);
    }
}

.title-paw svg {
    width: 100%;
    height: 100%;
    fill: var(--color-accent);
}

/* Story Section */
.story-content {
    max-width: 700px;
    margin: 0 auto;
    text-align: center;
}

.story-content p {
    margin-bottom: 2rem;
    font-size: 1.1rem;
}

/* Products Section */
.product-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.product-card {
    background: var(--color-white);
    padding: 2rem;
    text-align: center;
    transition: var(--transition-premium);
    border: 1px solid rgba(184, 134, 11, 0.15);
    position: relative;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.03);
}

.product-card:hover {
    transform: translateY(-15px);
    box-shadow: 0 20px 40px rgba(184, 134, 11, 0.1);
    border-color: var(--color-accent-soft);
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

.product-card:nth-child(2) { animation-delay: 1s; }
.product-card:nth-child(3) { animation-delay: 2s; }

.product-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--color-accent); /* Brass top line */
    transform: scaleX(0);
    transition: 0.4s ease;
}

.product-card:hover::before {
    transform: scaleX(1);
}

.product-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
}

.product-image {
    width: 100%;
    aspect-ratio: 1/1;
    overflow: hidden;
    margin-bottom: 1.5rem;
}

.product-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: 0.6s ease;
}

.product-card:hover .product-image img {
    transform: scale(1.05);
}

.product-card h3 {
    font-size: 2rem;
    margin-bottom: 0.8rem;
    color: var(--color-accent);
    letter-spacing: 0.1em;
    font-weight: 600;
    background: linear-gradient(135deg, var(--color-accent), var(--color-accent-soft));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 0 1px 2px rgba(0,0,0,0.05);
}

.price {
    color: var(--color-text-sub);
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.product-note {
    font-size: 0.75rem;
    color: #888;
    margin-bottom: 1.5rem;
    letter-spacing: 0.05em;
}

.btn-outline {
    display: inline-block;
    padding: 0.8rem 1.5rem;
    border: 1px solid var(--color-text-sub);
    color: var(--color-text-sub);
    font-size: 0.85rem;
}

.btn-outline:hover {
    background: var(--color-text-sub);
    color: var(--color-white);
}

/* Product Variations (Hover Reveal - Large Layout) */
.product-variations {
    display: flex;
    gap: 1.5rem;
    margin-top: 0;
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: 0.8s cubic-bezier(0.165, 0.84, 0.44, 1);
    width: 100%;
}

.product-card:hover .product-variations {
    max-height: 400px;
    opacity: 1;
    margin-top: 2rem;
    margin-bottom: 1rem;
}

/* Hide main info on hover to give space to variations (Target LP behavior) */
.product-card:hover .product-image,
.product-card:hover .product-note {
    display: none;
}

.variation {
    flex: 1;
    text-align: center;
    transition: 0.4s ease;
}

.variation:hover {
    transform: scale(1.03);
}

.variation img {
    width: 100%;
    aspect-ratio: 4/3;
    object-fit: cover;
    border-radius: 8px;
    margin-bottom: 1rem;
    box-shadow: 0 5px 15px rgba(0,0,0,0.08);
}

.variation span {
    display: block;
    font-size: 0.9rem;
    color: var(--color-accent-soft); /* Gold labels */
    font-family: var(--font-serif);
    font-weight: 500;
    letter-spacing: 0.05em;
}

/* Usage Section */
.usage-steps {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    max-width: 900px; /* 幅を広げて1行に対応 */
    margin: 0 auto;
}

.step {
    display: flex;
    align-items: center;
    gap: 3rem;
    white-space: nowrap;
    transition: var(--transition-premium);
    position: relative;
    cursor: pointer;
}

.step-hover-image {
    position: absolute;
    right: -50px;
    top: 50%;
    transform: translateY(-50%) translateX(20px) scale(0.9);
    width: 250px;
    height: 250px;
    object-fit: cover;
    border-radius: 15px;
    opacity: 0;
    pointer-events: none;
    box-shadow: 0 15px 40px rgba(0,0,0,0.15);
    transition: 0.5s cubic-bezier(0.165, 0.84, 0.44, 1);
    z-index: 10;
    border: 3px solid var(--color-white);
}

.step:hover .step-hover-image {
    opacity: 1;
    transform: translateY(-50%) translateX(0) scale(1);
}

.step:nth-child(2) { margin-left: 2rem; }
.step:nth-child(3) { margin-left: 4rem; }
.step:nth-child(4) { margin-left: 6rem; }
.step:nth-child(5) { margin-left: 8rem; }

.step-num {
    font-family: var(--font-serif);
    font-size: 3.5rem;
    color: var(--color-accent);
    line-height: 1;
    min-width: 100px;
    font-weight: 300;
    opacity: 0.6;
}

.step-content {
    display: flex;
    align-items: baseline;
    gap: 2rem;
}

.step h4 {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    color: var(--color-text-sub);
    min-width: 150px; /* タイトルの幅を揃える */
}

.step p {
    font-family: var(--font-serif);
    font-size: 1.1rem;
    color: var(--color-text-main);
}

/* Voice Section */
.voice-section {
    background: #FAFAFA;
}

.voice-hint {
    transition: opacity 0.5s ease;
}

.voice-section:hover .voice-hint {
    opacity: 0 !important;
}

.voice-content {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: all 1.2s cubic-bezier(0.165, 0.84, 0.44, 1);
}

.voice-section:hover .voice-content {
    max-height: 2000px;
    opacity: 1;
    margin-top: 2rem;
}

.voice-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    padding-bottom: 2rem;
}

.voice-card {
    background: var(--color-white);
    padding: 2.5rem 2rem 2rem;
    border-radius: 12px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.04);
    border: 1px solid rgba(184, 134, 11, 0.05);
    position: relative;
    transition: transform 0.3s ease;
}

.voice-card:hover {
    transform: translateY(-5px);
}

.voice-card::before {
    content: '“';
    position: absolute;
    top: 5px;
    left: 15px;
    font-size: 5rem;
    color: var(--color-accent-soft);
    opacity: 0.15;
    font-family: var(--font-serif);
    line-height: 1;
}

.voice-text {
    font-size: 1rem;
    line-height: 1.8;
    margin-bottom: 1.5rem;
    position: relative;
    z-index: 1;
    color: var(--color-text-main);
}

.voice-author {
    font-size: 0.9rem;
    color: var(--color-text-sub);
    text-align: right;
    font-weight: 600;
}

/* Social Impact Section */
.impact-section {
    background: #EFEBE9; /* Very soft warm grey-brown */
}

.impact-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.impact-message {
    font-family: var(--font-serif);
    font-size: 1.8rem;
    margin-bottom: 2rem;
    color: var(--color-text-sub);
}

/* Our Vision Section - Refined Gray Gradient */
.vision-section {
    background: linear-gradient(135deg, #F0F0F0 0%, #E0E0E0 100%);
    color: var(--color-text-main);
    border-top: 1px solid rgba(0,0,0,0.05);
    position: relative;
}

.vision-section .section-title {
    color: var(--color-text-sub);
}

.vision-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.vision-content p {
    margin-bottom: 1.5rem;
    opacity: 0.8;
}

.vision-content p:last-child {
    font-family: var(--font-serif);
    font-size: clamp(0.9rem, 2.5vw, 1.5rem);
    color: var(--color-accent);
    margin-top: 3rem;
    opacity: 1;
    white-space: nowrap;
}

/* Cat Footprint Cursor Trail Styles */
.cat-paw-trail {
    position: absolute; /* その場に留まるように修正 */
    width: 40px; 
    height: 40px;
    pointer-events: none;
    z-index: 10000;
    opacity: 0.6;
    animation: fadeOutPaw 3s forwards ease-out; /* 3秒に延長 */
}

@keyframes fadeOutPaw {
    0% { transform: scale(0.5) rotate(0deg); opacity: 0.6; }
    100% { transform: scale(1.2) rotate(10deg); opacity: 0; }
}

/* Static Decorations */
.static-paw {
    position: absolute;
    width: 30px;
    height: 30px;
    opacity: 0.1;
    pointer-events: none;
    fill: var(--color-text-sub);
}

/* Animations Scroll Trigger */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: 1.5s cubic-bezier(0.165, 0.84, 0.44, 1);
}

.animate-on-scroll.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive (Mobile Refinement) */
@media (max-width: 768px) {
    section {
        padding: 4rem 0;
    }
    
    .section-title {
        font-size: 2rem;
        margin-bottom: 3rem;
    }
    
    .product-grid {
        grid-template-columns: 1fr;
    }

    .product-card h3 {
        font-size: 1.5rem;
    }
    
    .step, 
    .step:nth-child(n) {
        flex-direction: column;
        gap: 0.5rem;
        text-align: center;
        align-items: center;
        margin-left: 0 !important; /* Reset staggered layout */
    }

    .step-num {
        font-size: 2.5rem;
        min-width: auto;
    }

    .step-content {
        flex-direction: column;
        gap: 0.5rem;
        align-items: center;
    }

    .step h4 {
        min-width: auto;
    }

    .step p {
        font-size: 1rem;
    }
    
    .impact-message {
        font-size: 1.3rem;
    }

    .vision-content p:last-child {
        white-space: normal;
        margin-top: 2rem;
    }

    .footer-links {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }

    /* Prevent overflow from decorations */
    .static-paw {
        display: none !important;
    }
    
    .step-hover-image {
        display: none !important;
    }

    /* Ensure sections clip overflow */
    section {
        overflow: hidden;
    }

    .hero-section {
        overflow: hidden;
    }

    .hero-content {
        overflow: hidden;
    }

    .story-content {
        overflow: hidden;
    }

    .usage-steps {
        overflow: hidden;
    }

    /* Voice section: always show on mobile (hover doesn't work on touch) */
    .voice-hint {
        display: none !important;
    }

    .voice-content {
        max-height: none !important;
        opacity: 1 !important;
    }

    .voice-grid {
        grid-template-columns: 1fr;
    }
}

/* Footer Refinement */
.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2rem;
}

.footer-logo {
    font-size: 2rem;
    letter-spacing: 0.2em;
    color: var(--color-text-sub);
}

.footer-links {
    display: flex;
    gap: 2rem;
}

.footer-links a {
    font-size: 0.9rem;
    border-bottom: 1px solid transparent;
}

.footer-links a:hover {
    border-bottom: 1px solid var(--color-text-main);
}